You have to use rEFIt. I could not get PCLOS to set up Grub to pick up OS-X. I installed rEFIt and tried again and got PCLOS to run, but it did not run right. I had problems with a lot of things. The mouse was very erratic, Linux could not find my external hard drive or the internal DVD burner and other stuff. I gave up for the time being. I may go back to it later.